1. Field of the Invention
This invention relates to a stop element which may be detachably secured to a well conduit at any desired axial position and anchored thereon to provide a stop for other tool elements slidably mounted on the conduit.
2. Description of the Prior Art
A large variety of stop devices have heretofore been proposed for mounting on well casings, liners, tubings and similar conduit strings, for engaging and moving other apparatus mounted on such strings through a well bore. Such devices should be capable of detachable securement to the particular conduit in any desired axial position thereon and should provide a sufficiently large radial abutment on such conduit as to insure that no other apparatus slidably mounted on the same conduit can pass over the stop device. Moreover, the stop device should preferably be fabricated from components produced by stamping operations in order to minimize the manufacturing costs thereof.
Conventional stop devices comprising two semi-annular elements interconnected by a hinge pin are commercially available. As will be obvious to those skilled in the art, the fabrication of hinge elements required machining operations so as to provide sufficient accuracy of the hinge apertures so that when the two elements are secured together by hinge pin, they will be in substantial axial alignment. Moreover, while a hinge connection provides relative pivotal movement of the two semi-annular elements of the stop device in a radial plane, it is well recognized that the hinge does not permit any movement of the two semi-annular elements in any plane other than that perpendicular to the axis of the hinge pin. Thus, if the two semi-annular elements are hinged together and are not precisely axially aligned, then when they are disposed in encompassing relationship to a well conduit, the non-hinged or free ends of the two semi-annular elements must be brought together with very substantial force to actually stretch the semi-annular elements into axial alignment with each other and into fully contacting relationship with the well conduit. If a bolt or other similar securing means is employed to effect the connection of the free ends, the bolt will appear to be very tight when this misalignment condition exists when actually very little clamping force is being exerted on the encompassed well conduit.